On Thu, May 23, 2013 at 02:09:10PM +0000, Christoph Lameter wrote: > On Thu, 23 May 2013, Peter Zijlstra wrote: > > > Right it doesn't. I think the easiest solution for now is to not copy the > > VMA > > on fork(). > > Right. Pinned pages are not inherited. If a page is unpinned then that is > going to happen for all address spaces that reference the page. > > > But I totally missed patch bc3e53f682d that introduced pinned_vm, AFAICT > > that > > also wrecked some accounting. We should still account both against > > RLIMIT_MEMLOCK. > > The point of the patch was to unwreck accounting. Before the patch mlocked > pages were counted twice which resulted in stramge VM scenarios where more > pages were mlocked than memory available. Note that a pinned page may also > be mlocked. > > Simply adding the two will reintroduce the problems that were fixed by the > patch.
The patch completely fails to explain how RLIMIT_LOCKED is supposed to deal with pinned vs locked. Perf used to account its pages against RLIMIT_LOCKED, with the patch it compares pinned against RLIMIT_LOCKED but completely discards any possible locked pages. IMO that's broken. -- To unsubscribe from this list: send the line "unsubscribe trinity" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
